removing lower unit "gear case" from 1959 evinrude 10hp

[tommr]

I want to remove the lower unit. I have removed the 4 - 7/16 bolts that holds the gear case to the mid section. I have also removed the shift connector window and the lower screw... the shift rod is now free but the lower unit will not slide out. It seems like the drive shaft is still connected somehow.
The book I am working from mentions that some year/models require pulling the power head to remove the lower unit.
Could this be one of those?
It looks like someone tried to remove this before as there is a good sized ding in the cavitation plate.
After cleaning up the carb and restoring the tank she started right up and we ran it for about a minute but shut down to check the gear oil and water pump.
Since the gear oil looks like a delicious creaming vanilla milkshake I want to inspect the seals etc.

Please help.

 

[AlTn]

Re: removing lower unit "gear case" from 1959 evinrude 10hp

removing the powerhead isn't necessary...I'd suggest this..stand the motor on the flywheel and allow penetrating oil <pb blaster, 50/50 mix of acetone and atf, liquid wrench, etc> to run down the driveshaft towards the crankshaft end...soak it like this over a few days applying at least a couple of times daily. Using some wooden wedges between the lower unit and the exhaust housing, try to gain some additional space each day. Hopefully, it'll separate completely in a few days. Would suggest to not get overly aggressive with the wedge banging, let time and soak work.

 

[tommr]

Re: removing lower unit "gear case" from 1959 evinrude 10hp

Thanks for the help, upside down it is.

 

[MaddysDaddy]

Re: removing lower unit "gear case" from 1959 evinrude 10hp

i had the same problem with a 73'? 10hp, the lower end was stuck so i pulled and pryed. When it finally came free, the water tube had pulled out of the powerhead and i was screwed. it should have slide of of the lower end, but someone had used some kind of sealant so it stuck to the waterpump. on my model motor this was a big problem as the copper water tube is not to b removed from the top. it is a big job to secure it properly.
I have only removed 3 lower units, the driveshaft pulled out of each end with out much force. sometime the water tube comes out of both ends. but beware.
Take your time!!

 

[tommr]

Re: removing lower unit "gear case" from 1959 evinrude 10hp

For crying out loud. I was taping wedges in the front and back of the space between the gear case and the midsection trying to make space to pour liquid wrench in and suddenly "pop" it came loose.
But....
The drive shaft is still in the motor and it pulled cleanly our of the lower unit.

What holds the drive shaft in the gear box???

I am hoping that I can put it back together like this.
The drive shaft is solid in the powerhead.
It slid right out after aligning with what was left of the water pump. Nothing but small pieces of rubber.
The water tube pulled out of the midsection but I have dealt with that before.
I did find the lower fill screw did not have a washer gasket and the upper washer gasket was shot so maybe that is where the water came from.

I wonder if I should split the case to inspect the gears?

 

[1946Zephyr]

Re: removing lower unit "gear case" from 1959 evinrude 10hp

Okay, now your impeller housing is probably broke. It's likely your drive shaft is siezed in the crank. It's a common issue, which happens after running for years without an o-ring on the top of the driveshaft and no lube on it. Fortunately, with ALL the motors I've worked with, I haven't seen this, but a few others here have. In a case like this, it's best to remove the screws from the impeller housing and slide the lower unit off, so just the drive shaft is left and that will make it easier to work with the drive shaft, to loosen it up.

 

[tommr]

Re: removing lower unit "gear case" from 1959 evinrude 10hp

1:30 am update.
I split the housing to check condition of seals and gears.
There is no indication of any means of securing the driveshaft to the gear inside the gear case. No loose screws, no broken threads.
And...
There is a slot in the water pump housing for the water pump drive nub to slide by.

Seals are shot and someone has been in there before with the wrong sized screwdriver I surmise by the shape of the screw heads.

 

[AlTn]

Re: removing lower unit "gear case" from 1959 evinrude 10hp

the pinion gear to driveshaft is a pressed fit, so you've exceeded the force it took join the two. The notch in the waterpump housing may have been created by a prior owner to deal with what you have now.Sooooo..now comes the kicker...getting the d/s out and , somehow, getting a tight enough fit into the pinion gear for the gearcase to work. Also, locating another waterpump housing and kit.
I, "fooled with" a 1958 10 hp. a while back and can share my experience with you as F_R and others did for me,

1. The weakness is the bronze bushing that the d/s passes through in the lower part of exhaust housing. The clearance between the d/s and bushing is virtually nil. In my case, I could move the d/s in the bushing, side to side, between 1/16 and 1/8". With this much clearance, there's no way the proper pinion to drive gear clearance can exist. One or the other is going to wear at a greatly accelerated rate.

2.Be careful removing the seals...especially the d/s seal in the plate under the waterpump. I took this plate out and gently tapped it out from the backside using a punch. Those plates are hard to find.

3.The seal in the bearing housing head is tough as well. If you try to use a seal puller, don't rest it on the "pot metal"end of the head <prop end> as that metal is really brittle and may break. I didn't remove this seal, but found a used bearing head and purchased it. The original head had chunks of metal missing from the prop end and I doubted that it would hold the seal.

4.Use 3M 347 sealer to join the gearcase halves together.

5.The rest of the story is this...new pinion gear $80. Seals $20 or so. Used bearing head from ebay $25 + shipping. Better, but used, lower exhaust housing $25. Gear shift bushing I mangaled getting it out $8. Will it stay in gear under load?..duuno..owners have yet to try it.

Summary..if your exhaust housing bushing is badly worn or out of round, you'll have to locate a better one or try to find another l/u altogether. I think there are other years that will work, I just don't know them. Probably not anything you wanted to hear, but that's one experience. Get the driveshaft out and study your options. Best of luck.

 

[tommr]

Re: removing lower unit "gear case" from 1959 evinrude 10hp

The shaft came out easy.
Here's how.
I took 3 jorgenson wood clamps and clamped them one at a time on the shaft. I put the shaft between the screws, closer to the front screw so I could clamp the bjesus out of the rear one. Stack up 3 like this. Cover the bottom clamp with a piece of junk plywood. ( these clamps are expensive ) Then get the 10lb hammer, and one swat and the d/s was out.

I checked the bushing and it is nice and tight so I am going to gently heat the pinion berring a tad, slip it over the end of the d/s and give it a good shot with the same hammer and a punch that matched the chamfered hole in the end of the shaft. The shot should tighten the clearance and when it cools down it will be tight.

 

[AlTn]

Re: removing lower unit "gear case" from 1959 evinrude 10hp

good to hear..I found that spray brake cleaner works well to clean the interior surfaces of the l/u and exhaust housing

 

[Chinewalker]

Re: removing lower unit "gear case" from 1959 evinrude 10hp

Be sure to replace that o-ring and grease the upper splines before reassembling!

 

[coolguy147]

Re: removing lower unit "gear case" from 1959 evinrude 10hp

this is the exact problem with my motor

i luckily found a parts motor of the 1960 year (almost identical except it used a fuel pump)
i checked the lower unit out and there was no side to side play in the driveshaft and it was tight with a good looking clutch dog.

i'm currently in the process of taking the seals out and replacing them

you can buy the seals right here on iboats and they have everything for a good deal.

you might have to replace your water pump housing as it might have been destroyed by the impeller key.

DON'T LOSE THE WOOD RUFF KEY THAT CONNECTS THE DRIVESHAFT TO THE PINION GEAR!

this happened to me and was thinking that my gears were stripped lol. i found it in the bottom when i took it apart.

BECAREFUL WITH THE TAKING THE SEALS OUT. they will break if force is used and they're expensive to replace.

 

[coolguy147]

Re: removing lower unit "gear case" from 1959 evinrude 10hp

where the seals are held in place will break lol